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Analysis

1. Which method (ballistic method or trajectory method) is more accurate in determiningthe initial speed of the ball?

- The Ballistic Method is more accurate to use in finding the initial speed ofthe ball. If we chose to use Trajectory Method, it is more prone to error

because we will need to obtain the horizontal displacement of the ball.

Since it is measured manually, the error in measuring is higher and will

more likely produce inaccurate results. While in Ballistic Method, we will

only need to acquire the increase in height of the pendulum in order to

compute the initial velocity.

2. In Part 1 of the Experiment, is the total momentum of the system conserved?Explain.

- Yes, the total momentum of the system is conserved. The Ballistic Methodis an example of a perfectly inelastic collision, with this, the total

momentum of the system is always conserved.

3. In Part 1 of the experiment, when is the total energy of the system not conserved?When is the total energy of the system conserved?- The total energy of the system is conserved during the collision. The total

momentum before an inelastic collision is the same as after the collision.

Since what is asked is the total energy not the total kinetic energy, the total

energy is conserved because the total kinetic energy before and after the

inelastic collision is different. Of course this does not mean that total

energy has not been conserved, rather the energy has been transformed

into another type of energy.

Conclusion

1. What causes the total momentum of the system to change?- Momentum, like mass, is also a conserved quantity, and there is a law

that states that "the momentum in an isolated system is constant". Thislaw is the law of conservation of momentum. The law of conservation of

momentum is very useful in the analysis of collisions and explosions as it

can be used to calculate the velocities of a body or bodies before and after

the collision. Since momentum is a conserved quantity, external

forces such as air resistance are the one that causes the total momentum

of a system to change.

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2. When the total momentum of the system is conserved, is the total energy of the systemconserved as well? Explain.

- Yes, both the energy and the momentum of the system are conserved. Inan elastic collision, both kinetic energy and momentum is conserved. In an

inelastic collision, the total momentum is also conserved but thetotal kinetic energy is not. An inelastic collision is usually accompanied by

deformation of one or both bodies. This requires energy thus; the total

energy is conserved but not necessarily the kinetic energy.

3. Is the total momentum of the system conserved in all kinds of collisions?Explain.

- Yes, the total momentum in all kinds of collisions is conserved. In an elastic collision,both energy and momentum is conserved. In an inelastic collision, the total

momentum is conserved but total kinetic energy is not conserved the kinetic energy

is transformed into other kinds of energy. Also, the law of conservation of

momentum states that the total momentum of the system before collision is equal

to the total momentum of the system after collision.